TRACE DETECTION OF RADIOTOXIC ISOTOPES BY RESONANCE IONIZATION MASS-SPECTROMETRY

Resonance ionization spectroscopy combined with mass spectrometry (RIMS) has become an important technique for ultratrace environmental analysis, and is particularly well suited for the detection of long-lived radiotoxic isotopes. A variety of experimental approaches have been developed to address the specific requirements posed by individual isotopes, which have widely differing physical, chemical, and environmental properties. In this paper we discuss the principles and recent progress in the development of three different methods that are being used for the analysis of radiotoxic species. These include measurement of actinides using triple-resonance ionization and time-of-flight mass spectrometry, development of a high efficiency laser ionization source primarily used for the detection of technetium isotopes, and collinear fast beam spectroscopy to provide extremely high isotopic selectivity necessary e.g. for the quantitative determination of Sr-89,Sr-90 in environmental samples.